1. Field of the Invention
This invention relates to resuscitating devices and, in particular, to a squeeze bag resuscitator.
2. Brief Statement of the Prior Art
Various devices have been developed for forced resuscitation. These devices have included inhalation-exhalation valves such as described in U.S. Pat. Nos. 3,616,813 and 3,435,839. These valves permit the pressured discharge of an oxygen containing gas into the patients mouth and cyclic reversal to withdraw waste gases from the patient in a sequential manner.
The resuscitating devices have been provided with flexible squeeze bags of approximately one liter capacity and which are manually squeezed by the therapist in a rhythmatic or cyclic operation. Typical of these devices is that described in U.S. Pat. Nos. 3,473,529 and 3,202,446.
Another approach utilizes the pressure of the available oxygen supply for the operation of the resuscitator. These devices employ valves to apply the positive pressure of the oxygen supply to the resuscitator in a cyclic manner. Typical of demand valves are those described in my prior U.S. Pat. Nos. 3,795,257 and 3,285,261.
None of the devices which have been developed heretofore have provided a variably adjustable proportionating control whereby the oxygen content of the breathing gas mixture delivered by the resuscitator can be varied in preselected, precise portions. While the squeeze bag devices are generally desirable to provide the therapist with a "feel" or feed-back of the patient's lung response, these devices do not permit variable adjustment of the proportions of oxygen in the delivered mixture nor precisely control the composition of the delivered gas mixture.